From f2c1aa1661edb3e14ff8b7b9995f93e303c8acbb Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Tue, 26 Jan 2016 00:40:57 +0100 Subject: [PATCH] Add ast.Constant Issue #26146: Add a new kind of AST node: ast.Constant. It can be used by external AST optimizers, but the compiler does not emit directly such node. An optimizer can replace the following AST nodes with ast.Constant: * ast.NameConstant: None, False, True * ast.Num: int, float, complex * ast.Str: str * ast.Bytes: bytes * ast.Tuple if items are constants too: tuple * frozenset Update code to accept ast.Constant instead of ast.Num and/or ast.Str: * compiler * docstrings * ast.literal_eval() * Tools/parser/unparse.py --- Include/Python-ast.h | 13 ++++- Include/asdl.h | 1 + Lib/ast.py | 52 +++++++++-------- Lib/test/test_ast.py | 120 +++++++++++++++++++++++++++++++++++++++- Misc/NEWS | 4 ++ Parser/Python.asdl | 7 ++- Parser/asdl.py | 3 +- Parser/asdl_c.py | 21 +++++++ Python/Python-ast.c | 79 ++++++++++++++++++++++++++ Python/ast.c | 50 +++++++++++++++++ Python/compile.c | 60 +++++++++++++++----- Python/future.c | 5 +- Python/symtable.c | 1 + Tools/parser/unparse.py | 29 +++++++++- 14 files changed, 401 insertions(+), 44 deletions(-) diff --git a/Include/Python-ast.h b/Include/Python-ast.h index 175e3808006..1ab376aba47 100644 --- a/Include/Python-ast.h +++ b/Include/Python-ast.h @@ -202,9 +202,9 @@ enum _expr_kind {BoolOp_kind=1, BinOp_kind=2, UnaryOp_kind=3, Lambda_kind=4, Await_kind=12, Yield_kind=13, YieldFrom_kind=14, Compare_kind=15, Call_kind=16, Num_kind=17, Str_kind=18, FormattedValue_kind=19, JoinedStr_kind=20, Bytes_kind=21, - NameConstant_kind=22, Ellipsis_kind=23, Attribute_kind=24, - Subscript_kind=25, Starred_kind=26, Name_kind=27, - List_kind=28, Tuple_kind=29}; + NameConstant_kind=22, Ellipsis_kind=23, Constant_kind=24, + Attribute_kind=25, Subscript_kind=26, Starred_kind=27, + Name_kind=28, List_kind=29, Tuple_kind=30}; struct _expr { enum _expr_kind kind; union { @@ -315,6 +315,10 @@ struct _expr { singleton value; } NameConstant; + struct { + constant value; + } Constant; + struct { expr_ty value; identifier attr; @@ -567,6 +571,9 @@ expr_ty _Py_NameConstant(singleton value, int lineno, int col_offset, PyArena *arena); #define Ellipsis(a0, a1, a2) _Py_Ellipsis(a0, a1, a2) expr_ty _Py_Ellipsis(int lineno, int col_offset, PyArena *arena); +#define Constant(a0, a1, a2, a3) _Py_Constant(a0, a1, a2, a3) +expr_ty _Py_Constant(constant value, int lineno, int col_offset, PyArena + *arena); #define Attribute(a0, a1, a2, a3, a4, a5) _Py_Attribute(a0, a1, a2, a3, a4, a5) expr_ty _Py_Attribute(expr_ty value, identifier attr, expr_context_ty ctx, int lineno, int col_offset, PyArena *arena); diff --git a/Include/asdl.h b/Include/asdl.h index 495153c576f..35e9fa18601 100644 --- a/Include/asdl.h +++ b/Include/asdl.h @@ -6,6 +6,7 @@ typedef PyObject * string; typedef PyObject * bytes; typedef PyObject * object; typedef PyObject * singleton; +typedef PyObject * constant; /* It would be nice if the code generated by asdl_c.py was completely independent of Python, but it is a goal the requires too much work diff --git a/Lib/ast.py b/Lib/ast.py index 017047275be..156a1f2773f 100644 --- a/Lib/ast.py +++ b/Lib/ast.py @@ -35,6 +35,8 @@ def parse(source, filename='', mode='exec'): return compile(source, filename, mode, PyCF_ONLY_AST) +_NUM_TYPES = (int, float, complex) + def literal_eval(node_or_string): """ Safely evaluate an expression node or a string containing a Python @@ -47,7 +49,9 @@ def literal_eval(node_or_string): if isinstance(node_or_string, Expression): node_or_string = node_or_string.body def _convert(node): - if isinstance(node, (Str, Bytes)): + if isinstance(node, Constant): + return node.value + elif isinstance(node, (Str, Bytes)): return node.s elif isinstance(node, Num): return node.n @@ -62,24 +66,21 @@ def literal_eval(node_or_string): in zip(node.keys, node.values)) elif isinstance(node, NameConstant): return node.value - elif isinstance(node, UnaryOp) and \ - isinstance(node.op, (UAdd, USub)) and \ - isinstance(node.operand, (Num, UnaryOp, BinOp)): + elif isinstance(node, UnaryOp) and isinstance(node.op, (UAdd, USub)): operand = _convert(node.operand) - if isinstance(node.op, UAdd): - return + operand - else: - return - operand - elif isinstance(node, BinOp) and \ - isinstance(node.op, (Add, Sub)) and \ - isinstance(node.right, (Num, UnaryOp, BinOp)) and \ - isinstance(node.left, (Num, UnaryOp, BinOp)): + if isinstance(operand, _NUM_TYPES): + if isinstance(node.op, UAdd): + return + operand + else: + return - operand + elif isinstance(node, BinOp) and isinstance(node.op, (Add, Sub)): left = _convert(node.left) right = _convert(node.right) - if isinstance(node.op, Add): - return left + right - else: - return left - right + if isinstance(left, _NUM_TYPES) and isinstance(right, _NUM_TYPES): + if isinstance(node.op, Add): + return left + right + else: + return left - right raise ValueError('malformed node or string: ' + repr(node)) return _convert(node_or_string) @@ -196,12 +197,19 @@ def get_docstring(node, clean=True): """ if not isinstance(node, (AsyncFunctionDef, FunctionDef, ClassDef, Module)): raise TypeError("%r can't have docstrings" % node.__class__.__name__) - if node.body and isinstance(node.body[0], Expr) and \ - isinstance(node.body[0].value, Str): - if clean: - import inspect - return inspect.cleandoc(node.body[0].value.s) - return node.body[0].value.s + if not(node.body and isinstance(node.body[0], Expr)): + return + node = node.body[0].value + if isinstance(node, Str): + text = node.s + elif isinstance(node, Constant) and isinstance(node.value, str): + text = node.value + else: + return + if clean: + import inspect + text = inspect.cleandoc(text) + return text def walk(node): diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py index d3e6d35943f..6d6c9bd26f9 100644 --- a/Lib/test/test_ast.py +++ b/Lib/test/test_ast.py @@ -1,7 +1,8 @@ +import ast +import dis import os import sys import unittest -import ast import weakref from test import support @@ -933,6 +934,123 @@ class ASTValidatorTests(unittest.TestCase): compile(mod, fn, "exec") +class ConstantTests(unittest.TestCase): + """Tests on the ast.Constant node type.""" + + def compile_constant(self, value): + tree = ast.parse("x = 123") + + node = tree.body[0].value + new_node = ast.Constant(value=value) + ast.copy_location(new_node, node) + tree.body[0].value = new_node + + code = compile(tree, "", "exec") + + ns = {} + exec(code, ns) + return ns['x'] + + def test_singletons(self): + for const in (None, False, True, Ellipsis, b'', frozenset()): + with self.subTest(const=const): + value = self.compile_constant(const) + self.assertIs(value, const) + + def test_values(self): + nested_tuple = (1,) + nested_frozenset = frozenset({1}) + for level in range(3): + nested_tuple = (nested_tuple, 2) + nested_frozenset = frozenset({nested_frozenset, 2}) + values = (123, 123.0, 123j, + "unicode", b'bytes', + tuple("tuple"), frozenset("frozenset"), + nested_tuple, nested_frozenset) + for value in values: + with self.subTest(value=value): + result = self.compile_constant(value) + self.assertEqual(result, value) + + def test_assign_to_constant(self): + tree = ast.parse("x = 1") + + target = tree.body[0].targets[0] + new_target = ast.Constant(value=1) + ast.copy_location(new_target, target) + tree.body[0].targets[0] = new_target + + with self.assertRaises(ValueError) as cm: + compile(tree, "string", "exec") + self.assertEqual(str(cm.exception), + "expression which can't be assigned " + "to in Store context") + + def test_get_docstring(self): + tree = ast.parse("'docstring'\nx = 1") + self.assertEqual(ast.get_docstring(tree), 'docstring') + + tree.body[0].value = ast.Constant(value='constant docstring') + self.assertEqual(ast.get_docstring(tree), 'constant docstring') + + def get_load_const(self, tree): + # Compile to bytecode, disassemble and get parameter of LOAD_CONST + # instructions + co = compile(tree, '', 'exec') + consts = [] + for instr in dis.get_instructions(co): + if instr.opname == 'LOAD_CONST': + consts.append(instr.argval) + return consts + + @support.cpython_only + def test_load_const(self): + consts = [None, + True, False, + 124, + 2.0, + 3j, + "unicode", + b'bytes', + (1, 2, 3)] + + code = '\n'.join(map(repr, consts)) + code += '\n...' + + code_consts = [const for const in consts + if (not isinstance(const, (str, int, float, complex)) + or isinstance(const, bool))] + code_consts.append(Ellipsis) + # the compiler adds a final "LOAD_CONST None" + code_consts.append(None) + + tree = ast.parse(code) + self.assertEqual(self.get_load_const(tree), code_consts) + + # Replace expression nodes with constants + for expr_node, const in zip(tree.body, consts): + assert isinstance(expr_node, ast.Expr) + new_node = ast.Constant(value=const) + ast.copy_location(new_node, expr_node.value) + expr_node.value = new_node + + self.assertEqual(self.get_load_const(tree), code_consts) + + def test_literal_eval(self): + tree = ast.parse("1 + 2") + binop = tree.body[0].value + + new_left = ast.Constant(value=10) + ast.copy_location(new_left, binop.left) + binop.left = new_left + + new_right = ast.Constant(value=20) + ast.copy_location(new_right, binop.right) + binop.right = new_right + + self.assertEqual(ast.literal_eval(binop), 30) + + def main(): if __name__ != '__main__': return diff --git a/Misc/NEWS b/Misc/NEWS index 676f2cac835..6e1a5a0d91b 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -10,6 +10,10 @@ Release date: tba Core and Builtins ----------------- +- Issue #26146: Add a new kind of AST node: ``ast.Constant``. It can be used + by external AST optimizers, but the compiler does not emit directly such + node. + - Issue #18018: Import raises ImportError instead of SystemError if a relative import is attempted without a known parent package. diff --git a/Parser/Python.asdl b/Parser/Python.asdl index 22775c68359..aaddf619e7c 100644 --- a/Parser/Python.asdl +++ b/Parser/Python.asdl @@ -1,4 +1,8 @@ --- ASDL's six builtin types are identifier, int, string, bytes, object, singleton +-- ASDL's 7 builtin types are: +-- identifier, int, string, bytes, object, singleton, constant +-- +-- singleton: None, True or False +-- constant can be None, whereas None means "no value" for object. module Python { @@ -76,6 +80,7 @@ module Python | Bytes(bytes s) | NameConstant(singleton value) | Ellipsis + | Constant(constant value) -- the following expression can appear in assignment context | Attribute(expr value, identifier attr, expr_context ctx) diff --git a/Parser/asdl.py b/Parser/asdl.py index 121cdab9520..62f5c19c99f 100644 --- a/Parser/asdl.py +++ b/Parser/asdl.py @@ -33,7 +33,8 @@ __all__ = [ # See the EBNF at the top of the file to understand the logical connection # between the various node types. -builtin_types = {'identifier', 'string', 'bytes', 'int', 'object', 'singleton'} +builtin_types = {'identifier', 'string', 'bytes', 'int', 'object', 'singleton', + 'constant'} class AST: def __repr__(self): diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py index eedd89bb32f..a81644d3b22 100644 --- a/Parser/asdl_c.py +++ b/Parser/asdl_c.py @@ -834,6 +834,7 @@ static PyObject* ast2obj_object(void *o) return (PyObject*)o; } #define ast2obj_singleton ast2obj_object +#define ast2obj_constant ast2obj_object #define ast2obj_identifier ast2obj_object #define ast2obj_string ast2obj_object #define ast2obj_bytes ast2obj_object @@ -871,6 +872,26 @@ static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena) return 0; } +static int obj2ast_constant(PyObject* obj, PyObject** out, PyArena* arena) +{ + if (obj == Py_None || obj == Py_True || obj == Py_False) { + /* don't increment the reference counter, Constant uses a borrowed + * reference, not a strong reference */ + *out = obj; + return 0; + } + + if (obj) { + if (PyArena_AddPyObject(arena, obj) < 0) { + *out = NULL; + return -1; + } + Py_INCREF(obj); + } + *out = obj; + return 0; +} + static int obj2ast_identifier(PyObject* obj, PyObject** out, PyArena* arena) { if (!PyUnicode_CheckExact(obj) && obj != Py_None) { diff --git a/Python/Python-ast.c b/Python/Python-ast.c index 07d9b3e8f7c..4dde11f00c1 100644 --- a/Python/Python-ast.c +++ b/Python/Python-ast.c @@ -306,6 +306,10 @@ static char *NameConstant_fields[]={ "value", }; static PyTypeObject *Ellipsis_type; +static PyTypeObject *Constant_type; +static char *Constant_fields[]={ + "value", +}; static PyTypeObject *Attribute_type; _Py_IDENTIFIER(attr); _Py_IDENTIFIER(ctx); @@ -709,6 +713,7 @@ static PyObject* ast2obj_object(void *o) return (PyObject*)o; } #define ast2obj_singleton ast2obj_object +#define ast2obj_constant ast2obj_object #define ast2obj_identifier ast2obj_object #define ast2obj_string ast2obj_object #define ast2obj_bytes ast2obj_object @@ -746,6 +751,26 @@ static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena) return 0; } +static int obj2ast_constant(PyObject* obj, PyObject** out, PyArena* arena) +{ + if (obj == Py_None || obj == Py_True || obj == Py_False) { + /* don't increment the reference counter, Constant uses a borrowed + * reference, not a strong reference */ + *out = obj; + return 0; + } + + if (obj) { + if (PyArena_AddPyObject(arena, obj) < 0) { + *out = NULL; + return -1; + } + Py_INCREF(obj); + } + *out = obj; + return 0; +} + static int obj2ast_identifier(PyObject* obj, PyObject** out, PyArena* arena) { if (!PyUnicode_CheckExact(obj) && obj != Py_None) { @@ -941,6 +966,8 @@ static int init_types(void) if (!NameConstant_type) return 0; Ellipsis_type = make_type("Ellipsis", expr_type, NULL, 0); if (!Ellipsis_type) return 0; + Constant_type = make_type("Constant", expr_type, Constant_fields, 1); + if (!Constant_type) return 0; Attribute_type = make_type("Attribute", expr_type, Attribute_fields, 3); if (!Attribute_type) return 0; Subscript_type = make_type("Subscript", expr_type, Subscript_fields, 3); @@ -2166,6 +2193,25 @@ Ellipsis(int lineno, int col_offset, PyArena *arena) return p; } +expr_ty +Constant(constant value, int lineno, int col_offset, PyArena *arena) +{ + expr_ty p; + if (!value) { + PyErr_SetString(PyExc_ValueError, + "field value is required for Constant"); + return NULL; + } + p = (expr_ty)PyArena_Malloc(arena, sizeof(*p)); + if (!p) + return NULL; + p->kind = Constant_kind; + p->v.Constant.value = value; + p->lineno = lineno; + p->col_offset = col_offset; + return p; +} + expr_ty Attribute(expr_ty value, identifier attr, expr_context_ty ctx, int lineno, int col_offset, PyArena *arena) @@ -3267,6 +3313,15 @@ ast2obj_expr(void* _o) result = PyType_GenericNew(Ellipsis_type, NULL, NULL); if (!result) goto failed; break; + case Constant_kind: + result = PyType_GenericNew(Constant_type, NULL, NULL); + if (!result) goto failed; + value = ast2obj_constant(o->v.Constant.value); + if (!value) goto failed; + if (_PyObject_SetAttrId(result, &PyId_value, value) == -1) + goto failed; + Py_DECREF(value); + break; case Attribute_kind: result = PyType_GenericNew(Attribute_type, NULL, NULL); if (!result) goto failed; @@ -6240,6 +6295,28 @@ obj2ast_expr(PyObject* obj, expr_ty* out, PyArena* arena) if (*out == NULL) goto failed; return 0; } + isinstance = PyObject_IsInstance(obj, (PyObject*)Constant_type); + if (isinstance == -1) { + return 1; + } + if (isinstance) { + constant value; + + if (_PyObject_HasAttrId(obj, &PyId_value)) { + int res; + tmp = _PyObject_GetAttrId(obj, &PyId_value); + if (tmp == NULL) goto failed; + res = obj2ast_constant(tmp, &value, arena); + if (res != 0) goto failed; + Py_CLEAR(tmp); + } else { + PyErr_SetString(PyExc_TypeError, "required field \"value\" missing from Constant"); + return 1; + } + *out = Constant(value, lineno, col_offset, arena); + if (*out == NULL) goto failed; + return 0; + } isinstance = PyObject_IsInstance(obj, (PyObject*)Attribute_type); if (isinstance == -1) { return 1; @@ -7517,6 +7594,8 @@ PyInit__ast(void) 0) return NULL; if (PyDict_SetItemString(d, "Ellipsis", (PyObject*)Ellipsis_type) < 0) return NULL; + if (PyDict_SetItemString(d, "Constant", (PyObject*)Constant_type) < 0) + return NULL; if (PyDict_SetItemString(d, "Attribute", (PyObject*)Attribute_type) < 0) return NULL; if (PyDict_SetItemString(d, "Subscript", (PyObject*)Subscript_type) < 0) diff --git a/Python/ast.c b/Python/ast.c index a5d8dbaee1b..5422e9c29b2 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -131,6 +131,50 @@ validate_arguments(arguments_ty args) return validate_exprs(args->defaults, Load, 0) && validate_exprs(args->kw_defaults, Load, 1); } +static int +validate_constant(PyObject *value) +{ + if (value == Py_None || value == Py_Ellipsis) + return 1; + + if (PyLong_CheckExact(value) + || PyFloat_CheckExact(value) + || PyComplex_CheckExact(value) + || PyBool_Check(value) + || PyUnicode_CheckExact(value) + || PyBytes_CheckExact(value)) + return 1; + + if (PyTuple_CheckExact(value) || PyFrozenSet_CheckExact(value)) { + PyObject *it; + + it = PyObject_GetIter(value); + if (it == NULL) + return 0; + + while (1) { + PyObject *item = PyIter_Next(it); + if (item == NULL) { + if (PyErr_Occurred()) { + Py_DECREF(it); + return 0; + } + break; + } + + if (!validate_constant(item)) { + Py_DECREF(it); + return 0; + } + } + + Py_DECREF(it); + return 1; + } + + return 0; +} + static int validate_expr(expr_ty exp, expr_context_ty ctx) { @@ -240,6 +284,12 @@ validate_expr(expr_ty exp, expr_context_ty ctx) return validate_expr(exp->v.Call.func, Load) && validate_exprs(exp->v.Call.args, Load, 0) && validate_keywords(exp->v.Call.keywords); + case Constant_kind: + if (!validate_constant(exp->v.Constant.value)) { + PyErr_SetString(PyExc_TypeError, "invalid type in Constant"); + return 0; + } + return 1; case Num_kind: { PyObject *n = exp->v.Num.n; if (!PyLong_CheckExact(n) && !PyFloat_CheckExact(n) && diff --git a/Python/compile.c b/Python/compile.c index a710e82693e..ccb05cf1ac8 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -1314,7 +1314,11 @@ compiler_isdocstring(stmt_ty s) { if (s->kind != Expr_kind) return 0; - return s->v.Expr.value->kind == Str_kind; + if (s->v.Expr.value->kind == Str_kind) + return 1; + if (s->v.Expr.value->kind == Constant_kind) + return PyUnicode_CheckExact(s->v.Expr.value->v.Constant.value); + return 0; } /* Compile a sequence of statements, checking for a docstring. */ @@ -1688,8 +1692,12 @@ compiler_function(struct compiler *c, stmt_ty s, int is_async) st = (stmt_ty)asdl_seq_GET(body, 0); docstring = compiler_isdocstring(st); - if (docstring && c->c_optimize < 2) - first_const = st->v.Expr.value->v.Str.s; + if (docstring && c->c_optimize < 2) { + if (st->v.Expr.value->kind == Constant_kind) + first_const = st->v.Expr.value->v.Constant.value; + else + first_const = st->v.Expr.value->v.Str.s; + } if (compiler_add_o(c, c->u->u_consts, first_const) < 0) { compiler_exit_scope(c); return 0; @@ -2599,6 +2607,36 @@ compiler_assert(struct compiler *c, stmt_ty s) return 1; } +static int +compiler_visit_stmt_expr(struct compiler *c, expr_ty value) +{ + if (c->c_interactive && c->c_nestlevel <= 1) { + VISIT(c, expr, value); + ADDOP(c, PRINT_EXPR); + return 1; + } + + if (value->kind == Str_kind || value->kind == Num_kind) { + /* ignore strings and numbers */ + return 1; + } + + if (value->kind == Constant_kind) { + PyObject *cst = value->v.Constant.value; + if (PyUnicode_CheckExact(cst) + || PyLong_CheckExact(cst) + || PyFloat_CheckExact(cst) + || PyComplex_CheckExact(cst)) { + /* ignore strings and numbers */ + return 1; + } + } + + VISIT(c, expr, value); + ADDOP(c, POP_TOP); + return 1; +} + static int compiler_visit_stmt(struct compiler *c, stmt_ty s) { @@ -2669,16 +2707,7 @@ compiler_visit_stmt(struct compiler *c, stmt_ty s) case Nonlocal_kind: break; case Expr_kind: - if (c->c_interactive && c->c_nestlevel <= 1) { - VISIT(c, expr, s->v.Expr.value); - ADDOP(c, PRINT_EXPR); - } - else if (s->v.Expr.value->kind != Str_kind && - s->v.Expr.value->kind != Num_kind) { - VISIT(c, expr, s->v.Expr.value); - ADDOP(c, POP_TOP); - } - break; + return compiler_visit_stmt_expr(c, s->v.Expr.value); case Pass_kind: break; case Break_kind: @@ -3625,6 +3654,8 @@ expr_constant(struct compiler *c, expr_ty e) switch (e->kind) { case Ellipsis_kind: return 1; + case Constant_kind: + return PyObject_IsTrue(e->v.Constant.value); case Num_kind: return PyObject_IsTrue(e->v.Num.n); case Str_kind: @@ -3912,6 +3943,9 @@ compiler_visit_expr(struct compiler *c, expr_ty e) return compiler_compare(c, e); case Call_kind: return compiler_call(c, e); + case Constant_kind: + ADDOP_O(c, LOAD_CONST, e->v.Constant.value, consts); + break; case Num_kind: ADDOP_O(c, LOAD_CONST, e->v.Num.n, consts); break; diff --git a/Python/future.c b/Python/future.c index 163f87f673d..75f210769e1 100644 --- a/Python/future.c +++ b/Python/future.c @@ -79,7 +79,10 @@ future_parse(PyFutureFeatures *ff, mod_ty mod, PyObject *filename) i = 0; first = (stmt_ty)asdl_seq_GET(mod->v.Module.body, i); - if (first->kind == Expr_kind && first->v.Expr.value->kind == Str_kind) + if (first->kind == Expr_kind + && (first->v.Expr.value->kind == Str_kind + || (first->v.Expr.value->kind == Constant_kind + && PyUnicode_CheckExact(first->v.Expr.value->v.Constant.value)))) i++; diff --git a/Python/symtable.c b/Python/symtable.c index 9f5149f8d0a..558bb06bd3a 100644 --- a/Python/symtable.c +++ b/Python/symtable.c @@ -1455,6 +1455,7 @@ symtable_visit_expr(struct symtable *st, expr_ty e) case JoinedStr_kind: VISIT_SEQ(st, expr, e->v.JoinedStr.values); break; + case Constant_kind: case Num_kind: case Str_kind: case Bytes_kind: diff --git a/Tools/parser/unparse.py b/Tools/parser/unparse.py index 99727978f8a..35ebc66d3e7 100644 --- a/Tools/parser/unparse.py +++ b/Tools/parser/unparse.py @@ -343,6 +343,11 @@ class Unparser: value = t.s.replace("{", "{{").replace("}", "}}") write(value) + def _fstring_Constant(self, t, write): + assert isinstance(t.value, str) + value = t.value.replace("{", "{{").replace("}", "}}") + write(value) + def _fstring_FormattedValue(self, t, write): write("{") expr = io.StringIO() @@ -364,6 +369,25 @@ class Unparser: def _Name(self, t): self.write(t.id) + def _write_constant(self, value): + if isinstance(value, (float, complex)): + self.write(repr(value).replace("inf", INFSTR)) + else: + self.write(repr(value)) + + def _Constant(self, t): + value = t.value + if isinstance(value, tuple): + self.write("(") + if len(value) == 1: + self._write_constant(value[0]) + self.write(",") + else: + interleave(lambda: self.write(", "), self._write_constant, value) + self.write(")") + else: + self._write_constant(t.value) + def _NameConstant(self, t): self.write(repr(t.value)) @@ -443,7 +467,7 @@ class Unparser: def _Tuple(self, t): self.write("(") if len(t.elts) == 1: - (elt,) = t.elts + elt = t.elts[0] self.dispatch(elt) self.write(",") else: @@ -490,7 +514,8 @@ class Unparser: # Special case: 3.__abs__() is a syntax error, so if t.value # is an integer literal then we need to either parenthesize # it or add an extra space to get 3 .__abs__(). - if isinstance(t.value, ast.Num) and isinstance(t.value.n, int): + if ((isinstance(t.value, ast.Num) and isinstance(t.value.n, int)) + or (isinstance(t.value, ast.Constant) and isinstance(t.value.value, int))): self.write(" ") self.write(".") self.write(t.attr)